Merge branch 'master' of https://bdgit.educoder.net/po2ap8csw/linux_lab_os_exp2
commit
dcceacef1c
@ -0,0 +1,317 @@
|
||||
/*
|
||||
* linux/kernel/system_call.s
|
||||
*
|
||||
* (C) 1991 Linus Torvalds
|
||||
*/
|
||||
|
||||
/*
|
||||
* system_call.s contains the system-call low-level handling routines.
|
||||
* This also contains the timer-interrupt handler, as some of the code is
|
||||
* the same. The hd- and flopppy-interrupts are also here.
|
||||
*
|
||||
* NOTE: This code handles signal-recognition, which happens every time
|
||||
* after a timer-interrupt and after each system call. Ordinary interrupts
|
||||
* don't handle signal-recognition, as that would clutter them up totally
|
||||
* unnecessarily.
|
||||
*
|
||||
* Stack layout in 'ret_from_system_call':
|
||||
*
|
||||
* 0(%esp) - %eax
|
||||
* 4(%esp) - %ebx
|
||||
* 8(%esp) - %ecx
|
||||
* C(%esp) - %edx
|
||||
* 10(%esp) - %fs
|
||||
* 14(%esp) - %es
|
||||
* 18(%esp) - %ds
|
||||
* 1C(%esp) - %eip
|
||||
* 20(%esp) - %cs
|
||||
* 24(%esp) - %eflags
|
||||
* 28(%esp) - %oldesp
|
||||
* 2C(%esp) - %oldss
|
||||
*/
|
||||
|
||||
SIG_CHLD = 17
|
||||
|
||||
EAX = 0x00
|
||||
EBX = 0x04
|
||||
ECX = 0x08
|
||||
EDX = 0x0C
|
||||
FS = 0x10
|
||||
ES = 0x14
|
||||
DS = 0x18
|
||||
EIP = 0x1C
|
||||
CS = 0x20
|
||||
EFLAGS = 0x24
|
||||
OLDESP = 0x28
|
||||
OLDSS = 0x2C
|
||||
|
||||
state = 0 # these are offsets into the task-struct.
|
||||
counter = 4
|
||||
priority = 8
|
||||
signal = 12
|
||||
sigaction = 16 # MUST be 16 (=len of sigaction)
|
||||
blocked = (33*16)
|
||||
|
||||
# offsets within sigaction
|
||||
sa_handler = 0
|
||||
sa_mask = 4
|
||||
sa_flags = 8
|
||||
sa_restorer = 12
|
||||
|
||||
nr_system_calls = 95 /* 72 */
|
||||
|
||||
/*
|
||||
* Ok, I get parallel printer interrupts while using the floppy for some
|
||||
* strange reason. Urgel. Now I just ignore them.
|
||||
*/
|
||||
.globl system_call,sys_fork,timer_interrupt,sys_execve,sys_execve2,sys_clone
|
||||
.globl hd_interrupt,floppy_interrupt,parallel_interrupt
|
||||
.globl device_not_available, coprocessor_error
|
||||
|
||||
.align 4
|
||||
bad_sys_call:
|
||||
movl $-1,%eax
|
||||
iret
|
||||
.align 4
|
||||
reschedule:
|
||||
pushl $ret_from_sys_call
|
||||
jmp schedule
|
||||
.align 4
|
||||
system_call:
|
||||
cmpl $nr_system_calls-1,%eax
|
||||
ja bad_sys_call
|
||||
push %ds
|
||||
push %es
|
||||
push %fs
|
||||
pushl %edx
|
||||
pushl %ecx # push %ebx,%ecx,%edx as parameters
|
||||
pushl %ebx # to the system call
|
||||
movl $0x10,%edx # set up ds,es to kernel space
|
||||
mov %dx,%ds
|
||||
mov %dx,%es
|
||||
movl $0x17,%edx # fs points to local data space
|
||||
mov %dx,%fs
|
||||
|
||||
pushl %eax #by wyj
|
||||
call print_nr
|
||||
popl %eax
|
||||
|
||||
call sys_call_table(,%eax,4)
|
||||
pushl %eax
|
||||
movl current,%eax
|
||||
cmpl $0,state(%eax) # state
|
||||
jne reschedule
|
||||
cmpl $0,counter(%eax) # counter
|
||||
je reschedule
|
||||
ret_from_sys_call:
|
||||
movl current,%eax # task[0] cannot have signals
|
||||
cmpl task,%eax
|
||||
je 3f
|
||||
cmpw $0x0f,CS(%esp) # was old code segment supervisor ?
|
||||
jne 3f
|
||||
cmpw $0x17,OLDSS(%esp) # was stack segment = 0x17 ?
|
||||
jne 3f
|
||||
movl signal(%eax),%ebx
|
||||
movl blocked(%eax),%ecx
|
||||
notl %ecx
|
||||
andl %ebx,%ecx
|
||||
bsfl %ecx,%ecx
|
||||
je 3f
|
||||
btrl %ecx,%ebx
|
||||
movl %ebx,signal(%eax)
|
||||
incl %ecx
|
||||
pushl %ecx
|
||||
call do_signal
|
||||
popl %eax
|
||||
3: popl %eax
|
||||
popl %ebx
|
||||
popl %ecx
|
||||
popl %edx
|
||||
pop %fs
|
||||
pop %es
|
||||
pop %ds
|
||||
iret
|
||||
|
||||
.align 4
|
||||
coprocessor_error:
|
||||
push %ds
|
||||
push %es
|
||||
push %fs
|
||||
pushl %edx
|
||||
pushl %ecx
|
||||
pushl %ebx
|
||||
pushl %eax
|
||||
movl $0x10,%eax
|
||||
mov %ax,%ds
|
||||
mov %ax,%es
|
||||
movl $0x17,%eax
|
||||
mov %ax,%fs
|
||||
pushl $ret_from_sys_call
|
||||
jmp math_error
|
||||
|
||||
.align 2
|
||||
device_not_available:
|
||||
push %ds
|
||||
push %es
|
||||
push %fs
|
||||
pushl %edx
|
||||
pushl %ecx
|
||||
pushl %ebx
|
||||
pushl %eax
|
||||
movl $0x10,%eax
|
||||
mov %ax,%ds
|
||||
mov %ax,%es
|
||||
movl $0x17,%eax
|
||||
mov %ax,%fs
|
||||
pushl $ret_from_sys_call
|
||||
clts # clear TS so that we can use math
|
||||
movl %cr0,%eax
|
||||
testl $0x4,%eax # EM (math emulation bit)
|
||||
je math_state_restore
|
||||
pushl %ebp
|
||||
pushl %esi
|
||||
pushl %edi
|
||||
call math_emulate
|
||||
popl %edi
|
||||
popl %esi
|
||||
popl %ebp
|
||||
ret
|
||||
|
||||
.align 4
|
||||
timer_interrupt:
|
||||
push %ds # save ds,es and put kernel data space
|
||||
push %es # into them. %fs is used by _system_call
|
||||
push %fs
|
||||
pushl %edx # we save %eax,%ecx,%edx as gcc doesn't
|
||||
pushl %ecx # save those across function calls. %ebx
|
||||
pushl %ebx # is saved as we use that in ret_sys_call
|
||||
pushl %eax
|
||||
movl $0x10,%eax
|
||||
mov %ax,%ds
|
||||
mov %ax,%es
|
||||
movl $0x17,%eax
|
||||
mov %ax,%fs
|
||||
incl jiffies
|
||||
movb $0x20,%al # EOI to interrupt controller #1
|
||||
outb %al,$0x20
|
||||
movl CS(%esp),%eax
|
||||
andl $3,%eax # %eax is CPL (0 or 3, 0=supervisor)
|
||||
pushl %eax
|
||||
call do_timer # 'do_timer(long CPL)' does everything from
|
||||
addl $4,%esp # task switching to accounting ...
|
||||
jmp ret_from_sys_call
|
||||
|
||||
.align 4
|
||||
sys_execve:
|
||||
lea EIP(%esp),%eax
|
||||
pushl %eax
|
||||
call do_execve
|
||||
addl $4,%esp
|
||||
ret
|
||||
|
||||
.align 4
|
||||
sys_execve2:
|
||||
lea EIP(%esp),%eax
|
||||
pushl %eax
|
||||
call do_execve2
|
||||
addl $4,%esp
|
||||
ret
|
||||
|
||||
.align 4
|
||||
sys_fork:
|
||||
call find_empty_process
|
||||
testl %eax,%eax
|
||||
js 1f
|
||||
push %gs
|
||||
pushl %esi
|
||||
pushl %edi
|
||||
pushl %ebp
|
||||
pushl %eax
|
||||
pushl $0x0 #for flag
|
||||
call copy_process
|
||||
addl $24,%esp #for flag
|
||||
1: ret
|
||||
|
||||
.align 4
|
||||
sys_clone:
|
||||
call find_empty_process
|
||||
testl %eax,%eax
|
||||
js 1f
|
||||
pushl %eax
|
||||
push %gs
|
||||
pushl %esi
|
||||
pushl %edi
|
||||
pushl %ebp
|
||||
pushl %eax
|
||||
pushl $0x1 #for flag
|
||||
call copy_process
|
||||
addl $24,%esp #for flag
|
||||
call do_clone
|
||||
addl $4,%esp
|
||||
1: ret
|
||||
|
||||
hd_interrupt:
|
||||
pushl %eax
|
||||
pushl %ecx
|
||||
pushl %edx
|
||||
push %ds
|
||||
push %es
|
||||
push %fs
|
||||
movl $0x10,%eax
|
||||
mov %ax,%ds
|
||||
mov %ax,%es
|
||||
movl $0x17,%eax
|
||||
mov %ax,%fs
|
||||
movb $0x20,%al
|
||||
outb %al,$0xA0 # EOI to interrupt controller #1
|
||||
jmp 1f # give port chance to breathe
|
||||
1: jmp 1f
|
||||
1: xorl %edx,%edx
|
||||
xchgl do_hd,%edx
|
||||
testl %edx,%edx
|
||||
jne 1f
|
||||
movl $unexpected_hd_interrupt,%edx
|
||||
1: outb %al,$0x20
|
||||
call *%edx # "interesting" way of handling intr.
|
||||
pop %fs
|
||||
pop %es
|
||||
pop %ds
|
||||
popl %edx
|
||||
popl %ecx
|
||||
popl %eax
|
||||
iret
|
||||
|
||||
floppy_interrupt:
|
||||
pushl %eax
|
||||
pushl %ecx
|
||||
pushl %edx
|
||||
push %ds
|
||||
push %es
|
||||
push %fs
|
||||
movl $0x10,%eax
|
||||
mov %ax,%ds
|
||||
mov %ax,%es
|
||||
movl $0x17,%eax
|
||||
mov %ax,%fs
|
||||
movb $0x20,%al
|
||||
outb %al,$0x20 # EOI to interrupt controller #1
|
||||
xorl %eax,%eax
|
||||
xchgl do_floppy,%eax
|
||||
testl %eax,%eax
|
||||
jne 1f
|
||||
movl $unexpected_floppy_interrupt,%eax
|
||||
1: call *%eax # "interesting" way of handling intr.
|
||||
pop %fs
|
||||
pop %es
|
||||
pop %ds
|
||||
popl %edx
|
||||
popl %ecx
|
||||
popl %eax
|
||||
iret
|
||||
|
||||
parallel_interrupt:
|
||||
pushl %eax
|
||||
movb $0x20,%al
|
||||
outb %al,$0x20
|
||||
popl %eax
|
||||
iret
|
||||
Loading…
Reference in new issue